Add Shop system with ShopManager, ShopUI, and ShopSlotUI; implement item purchasing and shop UI functionality

Assets/Scripts/Shop/ShopUI.cs

@@ -0,0 +1,83 @@
+using System;
+using System.Collections.Generic;
+using Inventory;
+using Systems;
+using TMPro;
+using UnityEngine;
+using UnityEngine.UI;
+
+namespace Shop
+{
+    public class ShopUI : MonoBehaviour
+    {
+        [SerializeField] private GameObject shopPanel;
+        [SerializeField] private Transform itemSlotParent;
+        [SerializeField] private Transform weaponSlotParent;
+        [SerializeField] private ShopSlotUI slotPrefab;
+        [SerializeField] private TextMeshProUGUI roundsText;
+        
+        private List<ShopSlotUI> currentSlots = new();
+
+        private void OnEnable()
+        {
+            GameManager.Instance.OnRoundEnd += UpdateRoundText;
+        }
+        
+        private void OnDisable()
+        {
+            GameManager.Instance.OnRoundEnd -= UpdateRoundText;
+        }
+
+        public void Show(List<StatModifierItem> items, List<WeaponItem> weapons, ShopManager shopManager)
+        {
+            GameManager.Instance.StoreIsClosed = false;
+            UpdateRoundText(GameManager.Instance.CurrentRound);
+            
+            shopPanel.SetActive(true);
+            ClearSlots();
+
+            foreach (var item in items)
+            {
+                var slot = Instantiate(slotPrefab, itemSlotParent);
+                slot.Setup(item, shopManager);
+                currentSlots.Add(slot);
+            }
+            
+            foreach (var weapon in weapons)
+            {
+                var slot = Instantiate(slotPrefab, weaponSlotParent);
+                slot.Setup(weapon, shopManager);
+                currentSlots.Add(slot);
+            }
+        }
+
+        public void Hide()
+        {
+            GameManager.Instance.StoreIsClosed = true;
+            shopPanel.SetActive(false);
+            ClearSlots();
+        }
+
+        public void MarkAsPurchased(ScriptableObject item)
+        {
+            foreach (var slot in currentSlots)
+            {
+                if (slot.MatchesItem(item)) slot.MarkAsPurchased();
+            }
+        }
+        
+        private void ClearSlots()
+        {
+            foreach (var slot in currentSlots) Destroy(slot.gameObject);
+            
+            currentSlots.Clear();
+        }
+        
+        private void UpdateRoundText(int round)
+        {
+            var nextRound = Mathf.Min(round + 1, GameManager.Instance.MaxRounds);
+            roundsText.text = $"Round: {nextRound}/{GameManager.Instance.MaxRounds}";
+        }
+
+    }
+}